diff --git a/suunto.h b/suunto.h
new file mode 100644
index 0000000..7778b56
--- /dev/null
+++ b/suunto.h
@@ -0,0 +1,29 @@
+#ifndef SUUNTO_VYPER_H
+#define SUUNTO_VYPER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+typedef struct vyper vyper;
+
+#define SUUNTO_VYPER_MEMORY_SIZE 0x2000
+#define SUUNTO_VYPER_PACKET_SIZE 32
+
+int suunto_vyper_open (vyper **device, const char* name);
+
+int suunto_vyper_close (vyper *device);
+
+int suunto_vyper_detect_interface (vyper *device);
+
+int suunto_vyper_read_dive (vyper *device, unsigned char data[], unsigned int size, int init);
+
+int suunto_vyper_read_memory (vyper *device, unsigned int address, unsigned char data[], unsigned int size);
+
+int suunto_vyper_write_memory (vyper *device, unsigned int address, const unsigned char data[], unsigned int size);
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* SUUNTO_VYPER_H */
diff --git a/suunto_test.c b/suunto_test.c
new file mode 100644
index 0000000..d6addb7
--- /dev/null
+++ b/suunto_test.c
@@ -0,0 +1,84 @@
+#include <stdio.h>	// fprintf
+
+#include "suunto.h"
+#include "serial.h"
+
+int main(int argc, char *argv[])
+{
+	unsigned char data[SUUNTO_VYPER_MEMORY_SIZE] = {0};
+
+#ifdef _WIN32
+	const char* name = "COM1";
+#else
+	const char* name = "/dev/ttyS0";
+#endif
+
+	if (argc > 1) {
+		name = argv[1];
+	}
+
+	vyper *device = NULL;
+
+	printf ("suunto_vyper_open\n");
+	int rc = suunto_vyper_open (&device, name);
+	if (rc != 0) {
+		fprintf (stderr, "%s:%d: Error opening serial port.\n",__FILE__,__LINE__);
+		return 1;
+	}
+
+	printf ("suunto_vyper_detect_interface\n");
+	rc = suunto_vyper_detect_interface (device);
+	if (rc != 0) {
+		fprintf (stderr, "%s:%d: Interface not found.\n",__FILE__,__LINE__);
+		suunto_vyper_close (device);
+		return 1;
+	}
+
+	printf ("suunto_vyper_read_memory\n");
+	rc = suunto_vyper_read_memory (device, 0x24, data, 1);
+	if (rc != 0) {
+		fprintf (stderr, "%s:%d: Cannot identify computer.\n",__FILE__,__LINE__);
+		suunto_vyper_close (device);
+		return 1;
+	}
+	rc = suunto_vyper_read_memory (device, 0x1E, data, 14);
+	if (rc != 0) {
+		fprintf (stderr, "Cannot read memory.\n");
+		suunto_vyper_close (device);
+		return 1;
+	}
+	rc = suunto_vyper_read_memory (device, 0x2C, data, 32);
+	if (rc != 0) {
+		fprintf (stderr, "Cannot read memory.\n");
+		suunto_vyper_close (device);
+		return 1;
+	}
+	rc = suunto_vyper_read_memory (device, 0x53, data, 30);
+	if (rc != 0) {
+		fprintf (stderr, "Cannot read memory.\n");
+		suunto_vyper_close (device);
+		return 1;
+	}
+
+	printf ("suunto_vyper_read_dive\n");
+	int ndives = 0;
+	do {
+		fprintf (stderr, "Reading dive #%d.\n", ndives + 1);
+		rc = suunto_vyper_read_dive (device, data, sizeof (data), (ndives == 0));
+		if (rc == -1) {
+			fprintf (stderr, "Cannot read dive.\n");
+			suunto_vyper_close (device);
+			return 1;
+		}
+		ndives++;
+	} while (rc > 0);
+
+	printf ("suunto_vyper_close\n");
+	rc = suunto_vyper_close (device);
+	if (rc != 0) {
+		fprintf (stderr, "Cannot close device.");
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/suunto_vyper.c b/suunto_vyper.c
new file mode 100644
index 0000000..9308d63
--- /dev/null
+++ b/suunto_vyper.c
@@ -0,0 +1,547 @@
+#include <stdio.h>	// fprintf
+#include <string.h> // memcmp, memcpy
+#include <stdlib.h> // malloc, free
+
+#include "suunto.h"
+#include "serial.h"
+
+#define MIN(a,b)	(((a) < (b)) ? (a) : (b))
+#define MAX(a,b)	(((a) > (b)) ? (a) : (b))
+
+
+struct vyper {
+	struct serial *port;
+	int extraanswertime;
+	int ifacealwaysechos;
+	int breakprofreadearly;
+};
+
+
+int
+suunto_vyper_open (vyper **out, const char* name)
+{
+	if (out == NULL)
+		return -1;
+
+	// Allocate memory.
+	struct vyper *device = malloc (sizeof (struct vyper));
+	if (device == NULL) {
+		fprintf (stderr, "%s:%d: Out of memory.\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+	// Set the default values.
+	device->port = NULL;
+	device->extraanswertime = 0;
+	device->ifacealwaysechos = 0;
+	device->breakprofreadearly = 0;
+
+	// Open the device.
+	int rc = serial_open (&device->port, name);
+	if (rc == -1) {
+		fprintf (stderr, "%s:%d: Can't open serial port %s.\n", __FILE__, __LINE__, name);
+		free (device);
+		return -1;
+	}
+
+	// Set the serial communication protocol (2400 8O1).
+	rc = serial_configure (device->port, 2400, 8, SERIAL_PARITY_ODD, 1, SERIAL_FLOWCONTROL_NONE);
+	if (rc == -1) {
+		fprintf (stderr, "%s:%d: Failed to set terminal attributes on %s.\n", __FILE__, __LINE__, name);
+		serial_close (device->port);
+		free (device);
+		return -1;
+	}
+
+	// Set the timeout for receiving data (500 ms).
+	if (serial_set_timeout (device->port, 500) == -1) {
+		fprintf (stderr, "%s:%d: Failed to set timeout on %s.\n", __FILE__, __LINE__, name);
+		serial_close (device->port);
+		free (device);
+		return -1;
+	}
+
+	// Set the DTR line (power supply for the interface) and clear
+	// the RTS line (toggle for the direction of the half-duplex interface).
+	if (serial_set_dtr (device->port, 1) == -1 ||
+		serial_set_rts (device->port, 0) == -1) {
+		fprintf (stderr, "%s:%d: Error setting RTS/DTR state on %s.\n", __FILE__, __LINE__, name);
+		serial_close (device->port);
+		free (device);
+		return -1;
+	}
+
+	// Give the interface 100 ms to settle and draw power up.
+	serial_sleep (100);
+
+	// Make sure everything is in a sane state.
+	serial_flush (device->port, SERIAL_QUEUE_BOTH);
+
+	*out = device;
+
+	return 0;
+}
+
+
+int
+suunto_vyper_close (vyper *device)
+{
+	if (device == NULL)
+		return 0;
+
+	// Close the device.
+	if (serial_close (device->port) == -1) {
+		free (device);
+		return -1;
+	}
+
+	// Free memory.	
+	free (device);
+
+	return 0;
+}
+
+
+static unsigned char
+suunto_vyper_checksum (const unsigned char data[], unsigned int size, unsigned char init)
+{
+	unsigned char crc = init;
+	for (unsigned int i = 0; i < size; ++i)
+		crc ^= data[i];
+
+	return crc;
+}
+
+
+static void
+suunto_vyper_reverse (unsigned char data[], unsigned int size)
+{
+	for (unsigned int i = 0; i < size / 2; ++i) {
+		unsigned char hlp = data[i];
+		data[i] = data[size-1-i];
+		data[size-1-i] = hlp;
+	}
+}
+
+
+static int
+suunto_vyper_send_testcmd (vyper *device, const unsigned char* data, unsigned int size)
+{
+	if (serial_write (device->port, data, size) != size) {
+		fprintf (stderr, "%s:%d: Trouble sending test sequence to interface.\n", __FILE__, __LINE__);
+		return -1;
+	}
+	serial_drain (device->port);
+	return 0;
+}
+
+
+int
+suunto_vyper_detect_interface (vyper *device)
+{
+	int rc, detectmode_worked = 1;
+	unsigned char command[3] = {'A', 'T', '\r'}, reply[3] = {0}, extra = 0;
+
+	if (device == NULL)
+		return -1;
+
+	// Make sure everything is in a sane state.
+	serial_flush (device->port, SERIAL_QUEUE_BOTH);
+
+	// Charge power supply?
+	serial_set_rts (device->port, 1);
+	serial_sleep (300);
+
+	// Try detection mode first.
+
+	serial_set_rts (device->port, 0);
+	if (suunto_vyper_send_testcmd (device, command, 3) == -1)
+		return -1;	// Failed to send? Huh?
+	rc = serial_read (device->port, reply, 3);
+	if (rc != 3 || memcmp (command, reply, 3) != 0) {
+    	fprintf (stderr, "%s:%d: Interface not responding in probe mode.\n", __FILE__, __LINE__);
+    	detectmode_worked = 0;
+	}
+	if (serial_read (device->port, &extra, 1) == 1) {
+		fprintf (stderr, "%s:%d: Got extraneous character %02x in detection phase - maybe line is connected to a modem?\n", __FILE__, __LINE__, extra);
+	}
+
+	// Try transfer mode now.
+
+	serial_set_rts (device->port, 1);
+	if (suunto_vyper_send_testcmd (device, command, 3) == -1)
+		return -1;	// Failed to send? Huh?
+	serial_set_rts (device->port, 0);
+	rc = serial_read (device->port, reply, 3);
+	if (rc == 0) {
+		if (detectmode_worked) {
+			fprintf (stderr, "%s:%d: Detected original suunto interface with RTS-switching.\n", __FILE__, __LINE__);
+		} else {
+			fprintf (stderr, "%s:%d: Can't detect Interface.\n"
+					"Hoping it's an original suunto interface with DC already attached.\n", __FILE__, __LINE__);
+		}
+		device->ifacealwaysechos = 0;
+		return 0;
+	}
+	if (rc != 3 || memcmp (command, reply, 3) != 0) {
+    	fprintf (stderr, "%s:%d: Interface not responding when RTS is on. Strange.\n", __FILE__, __LINE__);
+	}
+	if (serial_read (device->port, &extra, 1) == 1) {
+		fprintf (stderr, "%s:%d: Got extraneous character %02x in detection phase - maybe line is connected to a modem?\n", __FILE__, __LINE__, extra);
+	}
+	fprintf (stderr, "%s:%d: Detected clone interface without RTS-switching.\n", __FILE__, __LINE__);
+	device->ifacealwaysechos = 1;
+	return 0;
+}
+
+
+static int
+suunto_vyper_send_command (vyper *device, const unsigned char* data, unsigned int size)
+{
+	// Send the command to the dive computer.
+	serial_sleep (500);
+	serial_set_rts (device->port, 1);
+	serial_write (device->port, data, size);
+	serial_drain (device->port);
+	serial_sleep (200);
+	serial_set_rts (device->port, 0);
+
+	// If the interface sends an echo back (which is the case for many clone 
+	// interfaces), those echos should be removed from the input queue before 
+	// reading the real reply from the dive computer. Otherwise, the data 
+	// transfer will fail.
+	if (device->ifacealwaysechos) {
+		// Echos should be there instantly.
+		unsigned char echo[37] = {0}; // An echo is maximum 37 bytes long.
+		int rc = serial_read (device->port, echo, size);
+		if (rc != size || memcmp (data, echo, size) != 0) {
+			if (rc == 0) 
+				fprintf (stderr, "%s:%d: Timeout waiting for echos.\n", __FILE__, __LINE__);
+			else
+				fprintf (stderr, "%s:%d: Echo incorrect.\nMaybe another device is listening on this port?\n", __FILE__, __LINE__);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+
+static int
+suunto_vyper_read_memory_package (vyper *device, unsigned int address, unsigned char data[], unsigned int size)
+{
+	// Prepare the command.
+	unsigned char command[5] = {0x05,
+			(address >> 8) & 0xFF, // high
+			(address     ) & 0xFF, // low
+			size, // count
+			0x00};  // CRC
+	command[4] = suunto_vyper_checksum (command, 4, 0x00);
+
+	// Send the command to the dive computer.
+	if (suunto_vyper_send_command (device, command, 5) != 0) {
+		fprintf (stderr, "%s:%d: Error sending command.\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+	// FIXME: Give the DC extra answer time to send its first byte, 
+	//        then let the standard timeout apply.
+
+	// Receive the header of the package.
+	unsigned char reply[4] = {0, 0, 0, 0};
+	int rc = serial_read (device->port, reply, 4);
+	if (rc != 4 || memcmp (command, reply, 4) != 0) {
+		fprintf (stderr, "%s:%d: Reply to read memory malformed (expected %02x%02x%02x%02x, got %02x%02x%02x%02x).\n",
+			__FILE__, __LINE__,
+			command[0], command[1], command[2], command[3],
+			reply[0], reply[1], reply[2], reply[3]);
+		if (rc == 0) {
+			fprintf (stderr, "%s:%d: Interface present, but DC does not answer. Check connection.\n", __FILE__, __LINE__);
+		}
+		return -1;
+	}
+
+	// Receive the contents of the package.
+	rc = serial_read (device->port, data, size);
+	if (rc != size) {
+		fprintf (stderr, "%s:%d: Unexpected EOF in answer.\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+	// Calculate the checksum.
+	unsigned char ccrc = 0x00;
+	ccrc = suunto_vyper_checksum (reply, 4, ccrc);
+	ccrc = suunto_vyper_checksum (data, size, ccrc);
+
+	// Receive (and verify) the checksum of the package.
+	unsigned char crc = 0x00;
+	rc = serial_read (device->port, &crc, 1);
+	if (rc != 1 || ccrc != crc) {
+		fprintf (stderr, "%s:%d: Reply failed CRC check. Line noise?\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+#ifndef NDEBUG
+	printf ("VyperRead(0x%04x,%d)=\"", (command[1] << 8) | command[2], command[3]);
+	for (unsigned int i = 0; i < size; ++i) {
+		printf("%02x",data[i]);
+	}
+	printf("\"\n");
+#endif
+
+	return 0;
+}
+
+
+static int
+suunto_vyper_write_memory_prepare (vyper *device)
+{
+	// Prepare the commmand.
+	unsigned char command[3] = {0x07, 0xA5, 0x00};
+	command[2] = suunto_vyper_checksum (command, 2, 0x00);
+
+	// Send the command to the dive computer.
+	if (suunto_vyper_send_command (device, command, 3) != 0) {
+		fprintf (stderr, "%s:%d: Error sending command.\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+	// FIXME: Give the DC extra answer time to send its first byte, 
+	//        then let the standard timeout apply.
+
+	// Receive the header of the package.
+	unsigned char reply[3] = {0, 0, 0};
+	int rc = serial_read (device->port, reply, 3);
+	if (rc != 3 || memcmp (command, reply, 3) != 0) {
+		fprintf (stderr, "%s:%d: Reply to prepare write memory malformed (expected %02x%02x%02x, got %02x%02x%02x).\n",
+			__FILE__, __LINE__,
+			command[0], command[1], command[2],
+			reply[0], reply[1], reply[2]);
+		if (rc == 0) {
+			fprintf (stderr, "%s:%d: Interface present, but DC does not answer. Check connection.\n", __FILE__, __LINE__);
+		}
+		return -1;
+	}
+
+#ifndef NDEBUG
+	printf("VyperPrepareWrite();\n");
+#endif
+
+	return 0;
+}
+
+
+static int
+suunto_vyper_write_memory_package (vyper *device, int address, const unsigned char data[], unsigned int size)
+{
+	// Prepare the command.
+	unsigned char command[37] = {0x06,
+			(address >> 8) & 0xFF, // high
+			(address     ) & 0xFF, // low
+			size, // count
+			0x00};  // data + CRC
+	memcpy (command + 4, data, size);
+	command[size + 4] = suunto_vyper_checksum (command, size + 4, 0x00);
+
+	// Send the command to the dive computer.
+	if (suunto_vyper_send_command (device, command, size + 5) != 0) {
+		fprintf (stderr, "%s:%d: Error sending command.\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+	// FIXME: Give the DC extra answer time to send its first byte, 
+	//        then let the standard timeout apply.
+
+	// Receive the header of the package.
+	unsigned char reply[4] = {0, 0, 0, 0};
+	int rc = serial_read (device->port, reply, 4);
+	if (rc != 4 || memcmp (command, reply, 4) != 0) {
+		fprintf (stderr, "%s:%d: Reply to write memory malformed (expected %02x%02x%02x%02x, got %02x%02x%02x%02x).\n",
+			__FILE__, __LINE__,
+			command[0], command[1], command[2], command[3],
+			reply[0], reply[1], reply[2], reply[3]);
+		if (rc == 0) {
+			fprintf (stderr, "%s:%d: Interface present, but DC does not answer. Check connection.\n", __FILE__, __LINE__);
+		}
+		return -1;
+	}
+
+	// Calculate the checksum.
+	unsigned char ccrc = 0x00;
+	ccrc = suunto_vyper_checksum (reply, 4, ccrc);
+
+	// Receive (and verify) the checksum of the package.
+	unsigned char crc = 0x00;
+	rc = serial_read (device->port, &crc, 1);
+	if (rc != 1 || ccrc != crc) {
+		fprintf (stderr, "%s:%d: Reply failed CRC check. Line noise?\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+#ifndef NDEBUG
+	printf ("VyperWrite(0x%04x,%d,\"", (command[1] << 8) | command[2], command[3]);
+	for (unsigned int i = 0; i < size; ++i) {
+		printf ("%02x", command[i + 4]);
+	}
+	printf ("\");\n");
+#endif
+
+	return 0;
+}
+
+
+int
+suunto_vyper_read_memory (vyper *device, unsigned int address, unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return -1;
+
+	// The data transmission is split in packages
+	// of maximum $SUUNTO_VYPER_PACKET_SIZE bytes.
+
+	unsigned int nbytes = 0;
+	while (nbytes < size) {
+		// Calculate the package size.
+		unsigned int len = MIN (size - nbytes, SUUNTO_VYPER_PACKET_SIZE);
+
+		// Read the package.
+		if (suunto_vyper_read_memory_package (device, address + nbytes, data + nbytes, len) != 0)
+			return -1;
+
+		// Increment the total number of bytes read.
+		nbytes += len;
+	}
+
+	return 0;
+}
+
+
+int
+suunto_vyper_write_memory (vyper *device, unsigned int address, const unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return -1;
+
+	// The data transmission is split in packages
+	// of maximum $SUUNTO_VYPER_PACKET_SIZE bytes.
+
+	unsigned int nbytes = 0;
+	while (nbytes < size) {
+		// Calculate the package size.
+		unsigned int len = MIN (size - nbytes, SUUNTO_VYPER_PACKET_SIZE);
+
+		// Prepare to write the package.
+		if (suunto_vyper_write_memory_prepare (device) != 0)
+			return -1;
+
+		// Write the package.
+		if (suunto_vyper_write_memory_package (device, address + nbytes, data + nbytes, len) != 0)
+			return -1;
+
+		// Increment the total number of bytes written.
+		nbytes += len;
+	}
+
+	return 0;
+}
+
+
+int
+suunto_vyper_read_dive (vyper *device, unsigned char data[], unsigned int size, int init)
+{
+	if (device == NULL)
+		return -1;
+
+	// Prepare the command.
+	unsigned char command[3] = {init ? 0x08 : 0x09, 0xA5, 0x00};
+	command[2] = suunto_vyper_checksum (command, 2, 0x00);
+
+	// Send the command to the dive computer.
+	if (suunto_vyper_send_command (device, command, 3) != 0) {
+		fprintf (stderr, "%s:%d: Error sending command.\n", __FILE__, __LINE__);
+		return -1;
+	}
+
+	// FIXME: Give the DC extra answer time to send its first byte, 
+	//        then let the standard timeout apply.
+
+	// The data transmission is split in packages
+	// of maximum $SUUNTO_VYPER_PACKET_SIZE bytes.
+
+	unsigned int nbytes = 0;
+	for (;;) {
+		// Receive the header of the package.
+		unsigned char reply = 0;
+		int rc = serial_read (device->port, &reply, 1);
+		if (rc != 1 || memcmp (command, &reply, 1) != 0) {
+			// If no data is received at this point (timeout), 
+			// we assume the last package was already received
+			// and the transmission can be finished.
+			if (rc == 0)
+				break;
+			fprintf (stderr, "%s:%d: Unexpected answer start byte (%d).\n", __FILE__, __LINE__, reply);
+			return -1;
+		}
+
+		// Receive the size of the package.
+		unsigned char len = 0;
+		rc = serial_read (device->port, &len, 1);
+		if (rc != 1 || len > SUUNTO_VYPER_PACKET_SIZE) {
+			fprintf (stderr, "%s:%d: Unexpected answer length (%d).\n", __FILE__, __LINE__, len);
+			return -1;
+		}
+
+		// Receive the contents of the package.
+		unsigned char package[SUUNTO_VYPER_PACKET_SIZE] = {0};
+		rc = serial_read (device->port, package, len);
+		if (rc != len) {
+			fprintf (stderr, "%s:%d: Unexpected EOF in answer.\n", __FILE__, __LINE__);
+			return -1;
+		}
+
+		// Calculate the checksum.
+		unsigned char ccrc = 0x00;
+		ccrc = suunto_vyper_checksum (&reply, 1, ccrc);
+		ccrc = suunto_vyper_checksum (&len, 1, ccrc);
+		ccrc = suunto_vyper_checksum (package, len, ccrc);
+
+		// Receive (and verify) the checksum of the package.
+		unsigned char crc = 0x00;
+		rc = serial_read (device->port, &crc, 1);
+		if (rc != 1 || ccrc != crc) {
+			fprintf (stderr, "%s:%d: Unexpected answer CRC (%d).\n", __FILE__, __LINE__, crc);
+			return -1;
+		}
+
+		// Append the package to the output buffer.
+		if (nbytes + len <= size) {
+			memcpy (data + nbytes, package, len);
+			nbytes += len;
+		} else {
+			fprintf (stderr, "%s:%d: Insufficient buffer space available.\n", __FILE__, __LINE__);
+			return -1;
+		}
+
+		// If a package is smaller than $SUUNTO_VYPER_PACKET_SIZE bytes, 
+		// we assume it's the last packet and the transmission can be 
+		// finished early. However, this approach does not work if the 
+		// last packet is exactly $SUUNTO_VYPER_PACKET_SIZE bytes long!
+		if (device->breakprofreadearly && len != SUUNTO_VYPER_PACKET_SIZE) 
+			break;
+	}
+
+	// The DC traverses the internal ring buffer backwards while sending. 
+	// Therefore, we restore the original order before returning the 
+	// data to the application.
+	suunto_vyper_reverse (data, nbytes);
+
+#ifndef NDEBUG
+	printf ("Vyper%sProfile=\"", command[0] == 0x08 ? "First" : "");
+	for (unsigned int i = 0; i < nbytes; ++i) {
+		printf("%02x", data[i]);
+	}
+	printf("\"\n");
+#endif
+
+	return nbytes;
+}